Could someone explain why a game that is being shown at a Keiji Inafune panel means it's going to be developed by IGA instead of Keiji Inafune?
It was shown at Mighty No 9's panels, and if you know who was involved in raising awareness to the game, it was the company 8-4, who also assisted in the promotion videos. 8-4 have worked on at least two of IGA's games. It wouldn't surprise me if they too were getting behind this as they did with Mighty No 9, hence the teaser. Some of those at 8-4 also worked in magazine press, primarily EGM, which would explain the style of teasers for this and the other game shown at the event. I mean, why would the creator's name be intentionally obstructed? It's clearly not Inafune.
There were two mysterious ads from that booth, one of which is supposedly hinting at this game being IGA's, the one this thread is based upon. The "turning your world upside-down" is a Symphony of the Night reference, the image of the castle, and the image that looks similarly to the shrine stuff from Aria of Sorrow. If you want to look that deep, those are all either strange coincidences or references.